Sizing paper with stable dispersions of hydrocarbon resins

ABSTRACT

Disclosed are essentially stable aqueous dispersions of hydrocarbon resins which consist essentially of at least one hydrocarbon resin in finely-divided form; a water-soluble cationic resin, a specific example of which is a water-soluble cationic aminopolyamide--epichlorohydrin resin; and water. The dispersion can be used to size paper.

This is a division of application Ser. No. 413,065, filed Nov. 5, 1973now U.S. Pat. No. 3,941,736.

This invention relates to novel aqueous dispersions of hydrocarbonresins. Particularly, this invention relates to aqueous dispersionswhich consist essentially of finely-divided particles of at least onehydrocarbon resin, a water-soluble cationic polymeric dispersing agentfor the finely-divided particles, and water. The dispersing agent willbe detailed more fully hereinafter. The novel dispersions of thisinvention are useful in the sizing of paper.

In accordance with this invention there are provided aqueous dispersionsof hydrocarbon resin particles for use in the sizing of paper. Theaqueous dispersions of this invention have good stability (shelf life)for prolonged periods of time of up to about 3 to 6 months.

The dispersions of this invention consist essentially of, by weight,from about 5.5 parts to about 50 parts solids and from about 94.5 partsto about 50 parts water, the total of solids and water being 100 parts.The solids content consists essentially of, by weight, (a) from about 5parts to about 45 parts hydrocarbon resin particles (preferably fromabout 10 parts to about 40 parts) and (b) from about 0.5 part to about10 parts of a water-soluble cationic polymeric dispersing agent(preferably from about 1 part to about 8 parts). The dispersing agentwill be detailed more fully hereinafter. The dispersions of thisinvention require no dispersing agent other than component (b)dispersing agent.

Hydrocarbon resins employed in this invention are noncrystallinethermoplastic synthetic polymers having a ring and ball softening pointof from about 45° C. to about 150° C., preferably from about 50° C. toabout 120° C.; a molecular weight within the range of from about 350 toabout 2000, preferably from about 400 to 1400; and an acid number ofless than about 1. These hydrocarbon resins can be prepared by methodsknown in the art by homopolymerizing and copolymerizing ethylenicallyunsaturated hydrocarbon monomers containing only hydrogen and carbon intheir molecular structure.

Hydrocarbon resins meeting the above requirements can be derived fromliquid petroleum distillates boiling in the range of from about 20° C.to about 280° C., and preferably in the range of about 30° C. to about140° C., or any fraction boiling within these ranges. Petroleumhydrocarbon resins having the above properties and which are suitablefor use in this invention are disclosed and described in U.S. Pat. No.3,379,663, reference to which is hereby made.

Terpene resins having the above properties can also be employed incarrying out this invention.

In place of cracked petroleum distillates, unsaturated hydrocarboncompounds from other sources, alone or in admixture, can be used. Thus,synthetically derived ethylenically unsaturated hydrocarbons, alone orin admixture with other synthetically derived or naturally occurringethylenically unsaturated hydrocarbons, can be polymerized to producehydrocarbon resins for use in this invention. All that is required isthat the polymer have properties as above set out. Thus, relatively purehydrocarbon compounds such as diolefins and olefins can behomopolymerized or can be polymerized in admixture with varying amountsof cyclic diolefins or cyclic olefins, or both, or of substitutedbenzene hydrocarbons such as styrene, alpha-methyl styrene, vinyltoluene or divinyl benzene to produce resins having the aboveproperties. Various proportions of these unsaturated hydrocarbons of anyor all of the classes mentioned above can be mixed with certainfractions of cracked distillates to provide satisfactory materials forresin formation.

Hydrocarbon resins can be prepared by causing the hydrocarbons to reactin the presence of a suitable catalyst or activating agent or by the useof heat alone. The catalysts which can be used include acidic catalystssuch as AlCl₃, ZnCl₂, BF₃, H₂ SO₄, H₃ PO₄ and acid clays, anioniccatalysts such as metallic lithium and sodium or their alkylderivatives, metal coordinate catalysts such as aluminum triisobutyl andTiCl₄ or TiCl₃, and free radical catalysts such as benzoyl peroxide,cumene hydroperoxide, tertbutyl hydroperoxide, and hydrogen peroxide.Temperatures utilized will vary depending on the monomers and catalystsused and are well known in the art.

After the reaction is essentially complete, any residual catalyst can beremoved if required. Unreacted hydrocarbons and low molecular weightmaterials can be removed by vacuum or steam distillation, if desired,

The following resins are illustrative of hydrocarbon resins that can beused in this invention.

Resin A

A suitable hydrocarbon resin that can be used in this invention is apetroleum resin available commercially under the proprietary designationPiccopale 70. This resin has a ring and ball softening point of about70° C., a molecular weight of about 800, and an acid number of less than1.

Resin B

Another suitable petroleum hydrocarbon resin is that availablecommercially as Piccopale 100. This resin has a ring and ball softeningpoint of about 100° C., a molecular weight of about 1400, and an acidnumber of less than 1.

Resin C

Another hydrocarbon resin that can be used in this invention is a vinyltoluene-α-methyl styrene copolymer available commercially under theproprietary name Piccotex 120 which has a molecular weight of about 1400and a ring and ball softening point of about 120° C. The acid number ofthis resin is less than 1.

Resin D

Another resin that can be used in this invention is a vinyl toluenecopolymer that has been hydrogenated to an alpha value at 262millimicrons of less than 0.05. This resin has a ring and ball softeningpoint of about 135° C. and a molecular weight of about 1400. The acidnumber of this resin is less than about 1.

Resin E

Another resin that can be used in this invention is a vinyltoluene-α-methyl styrene copolymer available commercially under theproprietary name Piccotex 100. This resin has a molecular weight ofabout 1100 and a ring and ball softening point of about 100° C. The acidnumber of the resin is less than 1.

Resin F

Another suitable resin is that available under the proprietary namePetrosin 80, the average molecular weight of which ranges between about900 and 1000. It has a ring and ball softening point of 80±5° C.Petrosin 80 has an acid number less than 1.

Terpene resins are hydrocarbon resins and, as above set forth, thosehaving the properties above set forth can be used in this invention.Encyclopedia of Chemical Technology, Vol. 14, The InterscienceEncyclopedia, Inc., New York, 1955, reports that Southern sulfateturpentines are comprised of, by weight, 60% to 65% alpha-pinene and 25%to 35% beta-pinene. Refined Southern sulfate turpentine (200 parts) isadded dropwise to an agitated mixture of 450 parts dry toluene and 18parts aluminum chloride. The temperature during addition is held at 4°C. to 10° C. by cooling. The time of addition is 55 minutes. Reaction iscontinued at 8°-10° C. for 4 hours after turpentine addition iscomplete. Water (22° C.) is added with agitation while keeping thetemperature below 20° C. Fifteen minutes after water addition iscomplete, 45 parts calcium hydroxide is added and the mixture is warmedand held at 70° C. for 20 minutes. The hot mixture is filtered and thefilter cake is washed with toluene, and the washings are combined withthe product filtrate. When the filtrate cools, additional solids formwhich are separated by an additional filtration. The resulting filtrateis stripped using a heated oil bath for heat. Stripping is stopped at120 mm. pressure with the oil bath at 200° C. The residue is a softterpene hydrocarbon resin consisting of polymerization products ofterpene hydrocarbons and has a molecular weight of about 500 and a ringand ball softening point of about 75° C. Vacuum topping of this resinprovides a residue having a molecular weight of about 840 and a ring andball softening point of about 115° C.

In preparing aqueous hydrocarbon resin dispersions of this invention thehydrocarbon resin is first dissolved in a water-immiscible organicsolvent therefor such, for example, as benzene, xylene, chloroform, and1,2-dichloropropane. Mixtures of two or more solvents can be used ifdesired. The selected solvent will also be nonreactive to the componentsof the aqueous dispersion to be subsequently prepared.

The organic solvent--hydrocarbon resin solution is then mixed with anaqueous solution of cationic resin dispersing agent to provide anemulsion which is essentially unstable and in which the organicsolvent--hydrocarbon resin solution forms the dispersed phase. Theessentially unstable aqueous emulsion is then subjected to extreme shearto provide an essentially stable aqueous emulsion. Extreme shear isconveniently accomplished by means of an homogenizer. Thus passing, atleast once, the unstable aqueous emulsion through an homogenizer under apressure of the order of from about 1000 p.s.i.g. to about 8000p.s.i.g., will provide an essentially stable emulsion. Subsequently, theorganic solvent component of the emulsion is removed from the emulsionand there is provided an essentially stable aqueous dispersion ofhydrocarbon resin particles.

The aqueous hydrocarbon resin dispersions of this invention can beprepared by the inversion process. Thus, the hydrocarbon resin--organicsolvent solution is admixed with an aqueous solution of cationic resindispersing agent in an amount to provide a stable water-in-oil emulsionwhich is subsequently inverted to a stable oil-in-water emulsion by therapid addition of water with vigorous stirring. The organic solvent issubsequently removed as by distillation under reduced pressure.

The dispersing agents used to prepare the substantially stable aqueousdispersions of this invention are cationic polymeric resinous materialsthat are water-soluble.

Particularly suitable dispersing agents are the cationic thermosettablewater-soluble aminopolyamide--epichlorohydrin resins disclosed anddescribed in U.S. Pat. Nos. 2,926,116 and 2,926,154. These resins arewater-soluble polymeric reaction products of epichlorohydrin and anaminopolyamide. The aminopolyamide is derived by reaction of adicarboxylic acid and a polyalkylenepolyamine in a mole ratio ofpolyalkylenepolyamine to dicarboxylic acid of from about 0.8:1 to about1.4:1.

Particularly suitable dicarboxylic acids are diglycolic acid andsaturated aliphatic dicarboxylic acids containing from 3 through 10carbon atoms such as malonic acid, succinic acid, glutaric acid, adipicacid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

Other suitable dicarboxylic acids include terephthalic acid, isophthalicacid, phthalic acid, maleic acid, fumaric acid, itaconic acid,glutaconic acid, citraconic acid, and mesaconic acid.

The available anhydrides of the above acids can be used in preparing thewater-soluble aminopolyamide as well as the esters of the acids.Mixtures of two or more dicarboxylic acids, their anhydrides, and theiresters can be used to prepare the water-soluble aminopolyamides, ifdesired.

A number of polyalkylene polyamines, including polyethylene polyamines,polypropylene polyamines, polybutylene polyamines and the like can beemployed. Polyalkylene polyamines can be represented as polyamines inwhich the nitrogen atoms are linked together by groups of the formula--C_(n) N_(2n) -- where n is a small integer greater than unity and thenumber of such groups in the molecule ranges from two up to about eight.The nitrogen atoms can be attached to adjacent carbon atoms in the group--C_(n) H_(2n) -- or to carbon atoms farther apart, but not to the samecarbon atom. Polyamines such as diethylenetriamine,triethylenetetramine, tetraethylenepentamine, and dipropylenetriamine,which can be obtained in reasonably pure form are suitable for preparingwater-soluble aminopolyamides. Other polyalkylene polyamines that can beused include methyl bis-(3-aminopropyl)amine; methylbis-(2-aminoethyl)amine; and 4,7-dimethyltriethylenetetramine. Mixturesof polyalkylene polyamines can be used, if desired.

The spacing of an amino group on the aminopolyamide can be increased ifdesired. This can be accomplished by substituting a diamine such asethylenediamine, propylenediamine, hexamethylenediamine and the like fora portion of the polyalkylene polyamine. For this purpose, up to about80% of the polyalkylene polyamine can be replaced by a molecularlyequivalent amount of diamine. Usually, a replacement of about 50% orless will be adequate.

Temperatures employed for carrying out reaction between the dicarboxylicacid and the polyalkylene polyamine can vary from about 110° C. to about250° C. or higher at atmospheric pressure. For most purposestemperatures between about 160° C. and 210° C. are preferred. The timeof reaction will usually vary from about 1/2 hour to 2 hours. Reactiontime varies inversely with reaction temperatures employed.

In carrying out the reaction, it is preferred to use an amount ofdicarboxylic acid sufficient to react substantially completely with theprimary amine groups of the polyalkylene polyamine but insufficient toreact with the secondary amine groups and/or tertiary amine groups toany substantial extent. This will usually require a mole ratio ofpolyalkylene polyamine to dicarboxylic acid of from about 0.9:1 to about1.2:1. However, mole ratios of from about 0.8:1 to about 1.4:1 can beused. The aminopolyamide, derived as above described, is reacted withepichlorohydrin at a temperature of from about 45° C. to about 100° C.,and preferably between about 45° C. and 70° C., until the viscosity of a20% solids solution in water at 25° C. has reached about C or higher onthe Gardner-Holdt scale. This reaction is preferably carried out inaqueous solution to moderate the reaction. pH adjustment is usually notnecessary. However, since the pH decreases during the polymerizationphase of the reaction, it may be desirable, in some cases, to add alkalito combine with at least some of the acid formed. When the desiredviscosity is reached, water can be added to adjust the solids content ofthe resin solution to a desired amount, usually from about 2% to about50%.

In the aminopolyamide--epichlorohydrin reaction, satisfactory resultscan be obtained utilizing from about 0.1 mole to about 2 moles ofepichlorohydrin for each secondary or tertiary amine group of theaminopolyamide, and preferably from about 1 mole to about 1.5 moles ofepichlorohydrin.

A monofunctional alkylating agent can be employed as an additionalreactant in carrying out the above reaction, if desired. Amonofunctional alkylating agent can be first reacted with theaminopolyamide followed by reaction of the aminopolyamide-- alkylatingagent reaction product with epichlorohydrin, or the alkylating agent canbe reacted with the aminopolyamide--epichlorohydrin reaction product.Thus, for example, epichlorohydrin can be added to an aqueous solutionof the aminopolyamide at a temperature from about 45° C. to 55° C. Thereaction mixture is then heated at a temperature from about 50° C. to100° C., and preferably from about 60° C. to 80° C., depending upon therate of reaction desired. After a suitable time at this temperature,i.e., from about 10-100 minutes, and preferably until the viscosity ofan approximately 25% solids solution of the reaction mixture at 25° C.is from A to B on the Gardner-Holdt scale, at which time most of theepoxy groups of the epichlorohydrin have reacted with the amine groupsof the aminopolyamide, a monofunctional alkylating agent is added andthe reaction mixture heated, preferably at a temperature from about 60°C. to about 80° C., until the viscosity of an approximately 25% solidssolution at 25° C. is at least A and preferably at least B to C on theGardner-Holdt scale. The solids-viscosity relationship can be obtainedby direct reaction at the 25% level followed by dilution to 25% solids,or reaction at a lower level followed by concentration at less than 40°C. and under reduced pressure to 25% solids. Lower alkyl esters ofmineral acids such as the halides, sulfates and phosphates, substitutedalkyl halides, and the like are suitable monofunctional alkylatingagents. Illustrative of the compounds which can be used are dimethyl,diethyl and dipropyl sulfate; methyl chloride; methyl iodide; ethyliodide; methyl bromide; propyl bromide; and the mono-, di- ortri-methyl, ethyl and propyl phosphates. Certain aromatic compounds suchas benzyl chloride and methyl p-toluene sulfonate can be used. Fromabout 0.1 mole to about 0.9 mole of mono-functional alkylating agent foreach amine group can be used.

In the examples that follow, all parts and percentages are by weightunless otherwise specified. Sizing results are set forth in some of theexamples. Sizing results are determined on the Hercules Sizing Tester.The sizing test determines the resistance of a sized sheet of paper topenetration by No. 2 Test Solution, (an aqueous solution of, by weight,1.0% formic acid and 1.25% naphthol Green B). The time necessary for inkpenetration to reduce light reflectance either 80% or 85% (as indicatedin the examples) of the sheet's initial value is used to represent thedegree of sizing.

The two examples that follow are illustrative of the preparation of anaminopolyamide--epichlorohydrin resin, said resin being useful as acationic resin dispersing agent in this invention.

EXAMPLE 1

An aminopolyamide is formed by adding 219.3 parts of adipic acid slowly,with stirring, to 151.3 parts of diethylenetriamine in a flask fittedwith a stirrer and a condenser for collecting water distillate. Thereaction mixture is stirred and heated at 170°-180° C. under a nitrogenblanket until amide formation is complete. After air cooling toapproximately 140° C., hot water is added with stirring to provide a 50%solids solution of polyamide resin with an intrinsic viscosity of 0.140measured by using a 2% solution in 1 N NH₄ Cl. An epichlorohydrinderivative of the aminopolyamide is prepared by adding about 150 partsof water to about 50 parts of the 50% solids solution and then adding13.7 parts (0.149 mole) of epichlorohydrin. The reaction mixture isheated at 70° C. with stirring under a reflux condenser until theGardner-Holdt viscosity attains a value of D. The reaction mixture isdiluted with water to a solids content of about 10%.

EXAMPLE 2

An aminopolyamide is formed by adding 219.3 parts of adipic acid slowly,with stirring, to 151.3 parts of diethylenetriamine in a flask fittedwith a stirrer and a condenser for collecting water distillate. Thereaction mixture is stirred and heated at 170°-180° C. under a nitrogenblanket until amide formation is complete. After air cooling toapproximately 140° C., hot water is added with stirring to provide a 50%solids solution of polyamide resin with an intrinsic viscosity of 0.140measured by a 2% solution in 1 N NH₄ Cl. An epichlorohydrin derivativeof the aminopolyamide is prepared by adding about 110.25 parts of waterto about 50 parts of the 50% solids solution and then adding 14.4 parts(0.157 mole) of epichlorohydrin. The reaction mixture is heated at70°-75° C. with stirring under a reflux condenser until theGardner-Holdt viscosity attains a value of about E to F. The reactionmixture is diluted with water to a solids content of about 12.5%.

Other suitable dispersing agents that can be used in this invention arethe water-soluble alkylene polyamine--epichlorohydrin resins which arewater-soluble polymeric reaction products of epichlorohydrin and analkylene polyamine.

Alkylene polyamines which can be reacted with epichlorohydrin have theformula H₂ N(C_(n) H_(2n) NH)_(x) H wherein n is an integer 2 through 8and x is an integer 1 or more, preferably 1 through 6. Examples of suchalkylene polyamines are the alkylene diamines such as ethylenediamine;propylene diamine-1,2; propylene diamine-1,3; tetramethylenediamine; andhexamethylenediamine. The polyalkylene polyamines such as thepolyethylene polyamines, polypropylene polyamines, polybutylenepolyamines and the like are examples of alkylene polyamines that can beused. Specific examples of these polyalkylene polyamines includediethylenetriamine, triethylenetetramine, tetraethylenepentamine, anddipropylenetriamine. Other polyalkylene polyamines that can be usedinclude methyl bis(3-aminopropyl)amine; methyl bis(2-aminoethyl)amine;and 4,7-dimethyltriethylenetetramine. Mixtures of alkylene polyaminescan be used if desired.

The relative proportions of alkylene polyamine and epichlorohydrinemployed can be varied depending upon the particular alkylene polyamineused. In general, it is preferred that the molar ratio ofepichlorohydrin to alkylene polyamine be in excess of 1:1 and less than2:1. In the preparation of a water-soluble resin from epichlorohydrinand tetraethylenepentamine, good results are obtained at molar ratios offrom about 1.4:1 to 1.94:1. Reaction temperature is preferably in therange of from about 40° C. to about 60° C.

The following example illustrates the preparation of a dispersing agentof the above type.

EXAMPLE 3

To a mixture of 29.2 parts triethylenetetramine and 70 parts water isadded 44.4 parts epichlorohydrin over a period of about 12 minutes withperiodic cooling. After the epichlorohydrin addition is complete, thereaction mixture is heated to 75° C. and maintained at a temperature offrom about 70° C. to about 77° C. for about 33 minutes, at which pointthe Gardner-Holdt viscosity reached about I. The resulting reaction massis diluted with 592 parts water to provide an aqueous solution that hasa solids content of about 11.7% and a pH of about 6.3.

Another suitable dispersing agent for use in this invention is apoly(diallylamine)--epihalohydrin resin. Resins of this type can beprepared in accordance with the teachings of patent 3,700,623, referenceto which is hereby made.

A poly(diallylamine)--epihalohydrin resin is the resinous reactionproduct of (A) a linear polymer having units of the formula ##STR1##where R is hydrogen or lower alkyl and R' is hydrogen, alkyl or asubstituted alkyl group and (B) an eiphalohydrin.

In the above formula, each R can be the same or different and, asstated, can be hydrogen or lower alkyl. The alkyl groups contain from 1to 6 carbons and are preferably methyl, ethyl, isopropyl or n-butyl. R'of the formula represents hydrogen, alkyl or substituted alkyl groups.The R' alkyl groups will contain from 1 to 18 carbon atoms (preferablyfrom 1 to 6 carbon atoms) such as methyl, ethyl, propyl, isopropyl,butyl, tertbutyl, hexyl, octyl, decyl, dodecyl, tetradecyl, andoctadecyl. R' can also be a substituted alkyl group. Suitablesubstituents include, in general, any group which will not interferewith polymerization through a vinyl double bond. Typically, thesubstituents can be carboxylate, cyano, ether, amino (primary, secondaryor tertiary), amide, hydrazide and hydroxyl.

Polymers having units of the above formula can be produced bypolymerizing the hydrohalide salt of a diallylamine ##STR2## where R andR' are as indicated above, either alone or as a mixture with othercopolymerizable ingredients, in the presence of a free radical catalystand then neutralizing the salt to give the polymer free base.

Specific hydrohalide salts of the diallylamines which can be polymerizedto provide the polymer units of the invention include diallylaminehydrochloride; N-methyldiallylamine hydrochloride; N-methyldiallylaminehydrobromide; 2,2'-dimethyl-N-methyldiallylamine hydrochloride;N-ethyldiallylamine hydrobromide; N-isopropyldiallylamine hydrochloride;N-n-butyldiallylamine hydrobromide; N-tert-butyldiallylaminehydrochloride; N-n-hexyldiallylamine hydrochloride;N-octadecyldiallylamine hydrochloride; N-acetamidodiallylaminehydrochloride; N-cyanomethyldiallylamine hydrochloride;N-β-propionamidodiallylamine hydrobromide;N-carboethoxymethyldiallylamine hydrochloride;N-β-methoxyethyldiallylamine hydrobromide; N-β-aminoethyldiallylaminehydrochloride; N-hydroxyethyldiallylamine hydrobromide; andN-acetohydrazide substituted diallylamine hydrochloride.

Diallylamines and N-alkyldiallylamines, used to prepare the polymersemployed in this invention, can be prepared by the reaction of ammoniaor a primary amine with an allyl halide employing as a catalyst for thereaction a catalyst that promotes the ionization of the halide such, forexample, as sodium iodide, zinc iodide, ammonium iodide, cupric bromide,ferric chloride, ferric bromide, zinc chloride, mercuric iodide,mercuric nitrate, mercuric bromide, mercuric chloride, and mixtures oftwo or more. Thus, for example, N-methyldiallylamine can be prepared byreaction of two moles of an allyl halide, such as allyl chloride, withone mole of methylamine in the presence of an ionization catalyst suchas one of those enumerated above.

In preparing the homopolymers and copolymers, reaction can be initiatedby redox catalytic system. In a redox system, the catalyst is activatedby means of a reducing agent which produces free radicals without theuse of heat. Reducing agents commonly used are sodium metabisulfite andpotassium metabisulfite. Other reducing agents include water-solublethiosulfates and bisulfites, hydrosulfites and reducing salts such asthe sulfate of a metal which is capable of existing in more than onevalence state such as cobalt, iron, manganese and copper. A specificexample of such a sulfate is ferrous sulfate. The use of a redoxinitiator system has several advantages, the most important of which isefficient polymerization at lower temperatures. Conventional peroxidecatalysts such as tertiary-butyl hydroperoxide, potassium persulfate,hydrogen peroxide, and ammonium persulfate used in conjunction with theabove reducing agents or metal activators, can be employed.

As stated above, the linear polymers of diallylamines which are reactedwith an epihalohydrin can contain different units of formula (I) and/orcontain units of one or more other copolymerizable monomers. Typicallythe comonomer is a different diallylamine, a monoethylenicallyunsaturated compound containing a single vinyl or vinylidene group orsulfur dioxide, and is present in an amount ranging from 0 to 95 mole %of the polymer. Thus the polymers of diallylamine are linear polymerswherein from 5% to 100% of the recurring units have the formula (I) andfrom 0 to 95% of the recurring units are monomer units derived from (1)a vinylidene monomer and/or (2) sulfur dioxide. Preferred comonomersinclude acrylic acid, methacrylic acid, methyl and other alkyl acrylatesand methacrylates, acrylamide, methacrylamide, acrylonitrile,methacrylonitrile, vinyl acetate, vinyl ethers such as the alkyl vinylethers, vinyl ketones such as methyl vinyl ketone and ethyl vinylketone, vinyl sulfonamide, sulfur dioxide or a different diallylamineembraced by the above formula (II).

Specific copolymers which can be reacted with an epihalohydrin includecopolymers of N-methyldiallylamine and sulfur dioxide; copolymers ofN-methyldiallylamine and diallylamine; copolymers of diallylamine andacrylamide; copolymers of diallyl amine and acrylic acid; copolymers ofN-methyldiallylamine and methyl acrylate; copolymers of diallylamine andacrylonitrile; copolymers of N-methyldiallylamine and vinyl acetate;copolymers of diallylamine and methyl vinyl ether; copolymers ofN-methyldiallylamine and vinylsulfonamide; copolymers ofN-methyldiallylamine and methyl vinyl ketone; terpolymers ofdiallylamine, sulfur dioxide and acrylamide; and terpolymers ofN-methyldiallylamine, acrylic acid and acrylamide.

The epihalohydrin which is reacted with the polymer of a diallylaminecan be any epihalohydrin, i.e., epichlorohydrin, epibromohydrin,epifluorohydrin or epiiodohydrin and is preferably epichlorohydrin. Ingeneral, the epihalohydrin is used in an amount ranging from about 0.5mole to about 1.5 moles and preferably about 1 mole to about 1.5 molesper mole of secondary plus tertiary amine present in the polymer.

The poly(diallylamine)--epihalohydrin resin can be prepared by reactinga homopolymer or copolymer of a diallylamine as set forth above with anepihalohydrin at a temperature of from about 30° C. to about 80° C. andpreferably from about 40° C. to about 60° C. until the viscositymeasured on a solution containing 20% to 30% solids at 25° C. hasreached a range of A to E and preferably about C to D on theGardner-Holdt scale. The reaction is preferably carried out in aqueoussolution to moderate the reaction, and at a pH of from about 7 to about9.5.

When the desired viscosity is reached, sufficient water is added toadjust the solids content of the resin solution to about 15% or less andthe product cooled to room temperature (about 25° C.).

The poly(diallylamine)--epihalohydrin resin can be stabilized againstgelation by adding to the aqueous solution thereof sufficientwater-soluble acid (such as hydrochloric acid and sulfuric acid) toobtain and maintain the pH at about 2.

The following example illustrates the preparation of apoly(diallylamine)--epichlorohydrin resin.

EXAMPLE 4

A solution of 69.1 parts of methyldiallylamine and 197 parts of 20° Behydrochloric acid in 111.7 parts of demineralized water is sparged withnitrogen to remove air, then treated with 0.55 part of tertiary butylhydroperoxide and a solution of 0.0036 part of ferrous sulfate in 0.5part of water. The resulting solution is allowed to polymerize at60°-69° C. for 24 hours to give a polymer solution containing about52.1% solids with an RSV of 0.22. 122 parts of the above solution isadjusted to pH 8.5 by the addition of 95 parts of 3.8% sodium hydroxideand then diluted with 211 parts of water and combined with 60 parts ofepichlorohydrin. The mixture is heated at 45°-55° C. for 1.35 hoursuntil the Gardner-Holdt viscosity of a sample cooled to 25° C. reachesB+. The resulting solution is acidified with 25 parts of 20° Behydrochloric acid and heated at 60° C. until the pH becomes constant at2.0. The resulting resin solution has a solids content of 20.8% and aBrookfield viscosity = 77 cp. (measured using a Brookfield Model LVFViscometer, No. 1 spindle at 60 r.p.m. with guard).

The following examples are illustrative of the preparation of theaqueous dispersions of this invention.

EXAMPLE 5

A solution is prepared by dissolving 300 parts Resin F in 300 partsbenzene. This solution is thoroughly mixed with 500 parts (50 partssolids) of an epichlorohydrin modified aminopolyamide resin solutionprepared as in Example 1 diluted with 250 parts of water providing apremix which is homogenized twice at 3000 p.s.i. The resulting productis a stable oil-in-water emulsion from which substantially all of thebenzene is subsequently removed by distillation to a maximum pottemperature of about 100° C. The solids content of the resulting stablesuspension is about 35% (30% Resin F and 5% epichlorohydrin modifiedaminopolyamide resin). The dispersion is applied to 40 lb./3000 ft.²bleached kraft waterleaf paper in a size press in an amount sufficientto provide about 0.61% (dispersion solids) based on the weight of thepaper and the thus treated paper drum dried. Hercules sizing testresults show 240 seconds.

EXAMPLE 6

A solution is prepared by dissolving 300 parts Resin E in 300 partsbenzene. This solution is thoroughly mixed with 400 parts (50 partssolids) of an eipichlorohydrin modified aminopolyamide resin solutionprepared as in Example 2 diluted with 350 parts of water providing apremix which is homogenized twice at 3000 p.s.i. The resulting productis a stable oil-in-water emulsion from which substantially all of thebenzene subsequently is removed by distillation to a maximum pottemperature of about 100° C. The solids content of the resulting stablesuspension is about 35% (about 30% Resin E and about 5% epichlorohydrinmodified aminopolyamide resin).

It is to be understood that the above description and examples areillustrative of this invention and not in limitation thereof.

What I claim and desire to protect by Letters Patent is:
 1. In themethod of sizing paper wherein a hydrocarbon resin is applied to paperfibers in the process of preparing sized paper, the improvement whereinthere is employed in the sizing of the paper an essentially stableaqueous hydrocarbon resin dispersion consisting essentially of, byweight, from about 5.5 parts to about 50 parts solids and from about94.5 parts to about 50 parts water; the solids content consistingessentially of, by weight, (a) from about 5 parts to about 45 partshydrocarbon resin particles and (b) from about 0.5 part to about 10parts of a water-soluble cation polymeric dispersing agent, component(a) being a hydrocarbon resin from ethylenically unsaturated hydrocarbonmonomers having a ring and ball softening point of from about 45° C. toabout 150° C., a molecular weight of from about 350 to about 2000, andan acid number of less than about 1, component (b) being selected fromthe group consisting of (i) a water-solublepolyaminopolyamide--epichlorohydrin resin, (ii) a water-solublealkylenepolyamine--epichlorohydrin resin and (iii) a water-solublepoly(diallylamine)--epichlorohydrin resin.
 2. In the method of sizingpaper wherein a hydrocarbon resin is applied to paper fibers in theprocess of preparing sized paper, the improvement wherein there isemployed in the sizing of the paper an essentially stable aqueoushydrocarbon resin dispersion consisting essentially of, by weight, fromabout 5.5 parts to about 50 parts solids and from about 94.5 parts toabout 50 parts water; the solids content consisting essentially of, byweight, (a) from about 10 parts to about 40 parts hydrocarbon resinparticles and (b) from about 1 part to about 8 parts of a water-solublecation polymeric dispersing agent, component (a) being a hydrocarbonresin from ethylenically unsaturated hydrocarbon monomers having a ringand ball softening point of from about 45° C. to about 150° C., amolecular weight of from about 350 to about 2000, and an acid number ofless than about 1, component (b) being selected from the groupconsisting of (i) a water-soluble polyaminopolyamide--epichlorohydrinresin, (ii) a water-soluble alkylenepolyamine--epichlorohydrin resin and(iii) a water-soluble poly(diallylamine)--epichlorohydrin resin.
 3. Themethod of claim 3 wherein (a) of the aqueous dispersion is a hydrocarbonresin having a ring and ball softening point of from about 50° C. toabout 120° C., a molecular weight of from about 400 to about 1400, andan acid number less than about
 1. 4. The method of claim 3 wherein (b)of the aqueous dispersion is a water-solublepolyaminopolyamide--epichlorohydrin resin.
 5. The method of claim 4wherein the polyaminopolyamide moiety of the resin is from adipic acidand diethylenetriamine.
 6. The method of claim 3 wherein (b) of theaqueous dispersion is a water-soluble alkylenepolyamine--epichlorohydrinresin.
 7. The method of claim 3 wherein (b) of the aqueous dispersion isa water-soluble poly(diallylamine)--epichlorohydrin resin.